The present invention relates to computer networks, and more particularly, but not by way of limitation, to a phone Local Area Network (LAN) for providing broadband data communication between network elements over a two-wire medium.
As prices for computers and peripherals decrease more homes and small business are increasing the number of computers and peripherals present in these computing environments. As the number of computers, peripherals, and other automated equipment, such as computerized home appliances, increases in the home or small business environments, it is increasingly important for such elements to be interconnected, for example, in a Local Area Network or LAN configuration. Interconnection allows hardware resources, such as printers, to be shared between a number of computers or accessed from many locations, allows high speed data transfer between devices, and further allows devices to be controlled remotely by other devices in the network.
Many high speed networking alternatives are available for large businesses but such alternatives require a large investment in networking resources. In contrast, choices for a home or small business network are limited by practical and economic factors such as the cost of the new wiring or cabling, especially given that utility wiring may already exist at the respective premises. It should be understood that the cost associated with rewiring a home to provide cable capable of carrying signals at network frequencies can be prohibitive.
Ethernet technology is commonly used in businesses for providing network connectivity, and has evolved into successively more robust forms over many years. One commonly used baseband Ethernet technology is known as the 10BASE-T network. The 10BASE-T network has an operating rate of 10 Mbps, is compliant with LAN 802.3 standards and specifications, and thereby provides moderate to high speed interconnectivity between many workstations and peripherals for most applications.
In a conventional business LAN application, workstations and peripherals, such as printers and disk towers, are wired together to allow shared access, data transfer, and communication between individual user workstations and network devices. A typical 10BASE-T network interface card (NIC) is located at each workstation and network device and accommodates two pairs of (category 5) unshielded twisted-pair wires. Under the 10BASE-T standard, one twisted pair is used for data transmission and another twisted pair is used for data reception. Due to the specialized nature of the interface circuitry and the common mode noise rejecting capability of the xe2x80x9ctwistedxe2x80x9d configuration of the actual wire pair or, alternatively, the noise rejecting capability of shielded coaxial cable, relatively high data rates may be achieved. In the typical home, however, existing coaxial cables for cable TV service cannot be used to transmit data because of the resulting signal interference, and twisted wires pairs are unavailable. Accordingly, high data rate networks are not possible without expensive rewiring.
Some proposed solutions to home networking include standard modem technology, digital subscriber line (xDSL) technology, and wireless technology. Standard modem technology has traditionally been limited to data speeds of 56 kbps and requires very complicated circuitry and high quality line characteristics not readily available in a typical home. Although, xDSL technology can transmit data at a much higher rate than standard modem technology, the cost of implementation of xDSL is at present very high and requires very complicated modulation methods. High quality line characteristics, such as signal-to-noise ratio, may also be required with xDSL technology to meet theoretical objectives.
Wireless solutions allow for connectivity between elements, typically using frequencies around 900 MHz, but have certain drawbacks. Since wireless portable phones are often operated in neighboring bands, there is a high likelihood of signal interference between a wireless LAN and portable phones or household devices, such as televisions, computers, garage door openers, alarm systems, and the like.
Despite the many potential solutions to home and small business networking, problems arise in providing LAN type networking in view of the presence of existing customer premises traffic whether voice traffic, xDSL traffic, or both. In addition, the cost associated with independent wiring to accommodate LAN networking on the customer premises has been prohibitive.
Therefore, as can be appreciated, there is a need to provide LAN compliant home networking that is available at a low cost, and that can provide high data rates while taking advantage of existing four wire phone lines without disrupting existing traffic.
The present invention overcomes the above-identified problems, as well as other shortcomings and deficiencies of existing technologies, by providing a phone Local Area Network (LAN), including a phone HUB for routing LAN traffic between network elements within the customer premises and for routing analog and digital traffic from a Public Switched Telephone Network (PSTN) to network elements and telephone sets within the customer premises.
The phone hub of the present invention may be coupled between the PSTN and particular Customer Premises.Equipment (CPE). One or more network elements, each having a specially adapted network interface controller (NIC), are interconnected through the customer premises wiring plant and a router. Analog voice signals are transparently transferred from the PSTN to the customer premises wiring plant through the phone hub using a splitter, such that voice traffic in either direction is unaffected by the presence or the absence of digital data. Inbound digital data, advanced DSL or ADSL data for example, separated from voice signals at the splitter at a first frequency, is transported using the router at a second higher frequency to a specially adapted NIC at each network element. Outbound digital data at the first frequency is transported to the router at the second frequency by the specially adapted NIC. Outbound digital data transported at the second frequency may be frequency shifted by the router back to the first frequency for transport in the conventional manner over the PSTN.
The specially adapted NIC operates at broadband 10BASE-T Ethernet frequencies and can accommodate common telephone connectors, such as RJ-11 style connectors used in standard residential telephone communications. A Media Access Control (MAC) function of such a specially adapted NIC provides one fixed frequency channel, a frequency channel at a higher range, such as the range at 1 MHz above the ADSL range from about 2-3 MHZ would be occupied by 802.3 LAN traffic at 8 Mbps.
Standard telephone units are accommodated by the phone LAN in that standard RJ-11 style connectors and the customer premises wiring plant are used. The phone hub provides an interface between the local loop connection and the customer premises wiring. By plugging into, for example, the standard RJ-11 wall outlet, a standard telephone unit would receive the 4 KHz analog voice band channel routed transparently through the splitter for reception by any standard telephone unit of standard voice traffic whether or not phone LAN traffic was being processed at the higher frequency bands.